1. Field of the Invention
The present invention relates to an organic thin film transistor and a manufacturing method thereof.
2. Description of the Related Art
A flat panel display such as a liquid crystal display (LCD), an organic light emitting diode (OLED) display, an electrophoretic display, etc., may include pairs of field generating electrodes combined with electro-optical active layers disposed between the field generating electrodes. The electro-optical layers may be, e.g., liquid crystal layers in the LCD, organic light emitting layers in the OLED display, etc.
One of the field generating electrodes may be coupled to a switching element and may receive electrical signals from the switching element. A common switching element for flat panel displays is a three-terminal thin film transistor (TFT). The electro-optical layer may then convert the electrical signals into optical signals to display images.
The flat panel display may further include signal lines, e.g., gate lines and data lines. The gate lines may transmit scanning signals for controlling the TFTs and the data lines may transmit data signals to be applied to the field generating electrodes through the TFTs.
Recently, interest in organic thin film transistors (OTFTs) has increased. OTFTs may employ an organic semiconductor instead of an inorganic, e.g., silicon, semiconductor. OTFTs have characteristics that may be advantageous in the manufacture of flat panel displays. For example, OTFTs may be manufactured using a low temperature solution process and, thus, may be advantageously applied to the manufacture of large display devices, which may be difficult to manufacture using the deposition processes conventionally required for inorganic semiconductors. Additionally, OTFTs may be easily formed in fibers or films due to the characteristics of the organic material, and thus may be suitable for use in flexible display devices.
The OTFT may include a channel region of organic semiconductor, which may be formed by dissolving the organic semiconductor into a solvent to make a solution and coating the solution on a substrate. However, such formation of the channel region may require precise control of the deposition of the solution in order to exactly control the size of the channel layers and, thus, obtain uniform operational characteristics of the OTFTs.